Representative Figure Method for Proximity Effect Correction

Abstract

A new concept for proximity effect correction (the representative figure method) is proposed in order to greatly reduce the correction time. The method assigns only one representative rectangle within a small area whose size is sufficiently smaller than the backscattering range of electrons. Proximity effect correction is carried out by using representative figures instead of the original patterns. This method eliminates the pattern density dependence of the correction time because the pattern density of the representative figures does not exceed the number of small areas. The relative error caused by the representative figure method is at most ±1% for a Ghost-scheme exposure and ±3-4% for the dose correction method.